[PATCH] move irq_enter and irq_exit to common code

This code is the same for all architectures with the following invariants:

- arm gurantees irqs are disabled when calling irq_exit so it can call
  __do_softirq directly instead of do_softirq

- arm26 is totally broken for about half a year, I didn't care for it

- some architectures use softirq_pending(smp_processor_id()) instead of
  local_softirq_pending, but they always evaluate to the same

This patch moves the out of line irq_exit implementation from
kernel/irq/handle.c which depends on CONFIG_GENERIC_HARDIRQS to
kernel/softirq.c which is always compiled, tweaks it for the arm special
case and moves the irq_enter/irq_exit/nmi_enter/nmi_exit bits from
asm-*/hardirq.h to linux/hardirq.h

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 17 insertions, 11 deletions

diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index ebc25823b73da9..2fb0e46e11f390 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -73,17 +73,6 @@ irqreturn_t no_action(int cpl, void *dev_id, struct pt_regs *regs)
 }
 
 /*
- * Exit an interrupt context. Process softirqs if needed and possible:
- */
-void irq_exit(void)
-{
-	preempt_count() -= IRQ_EXIT_OFFSET;
-	if (!in_interrupt() && local_softirq_pending())
-		do_softirq();
-	preempt_enable_no_resched();
-}
-
-/*
  * Have got an event to handle:
  */
 fastcall int handle_IRQ_event(unsigned int irq, struct pt_regs *regs,
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 7572ca9ece74a4..8d6e9055e2b910 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -152,6 +152,23 @@ void local_bh_enable(void)
 }
 EXPORT_SYMBOL(local_bh_enable);
 
+#ifdef __ARCH_IRQ_EXIT_IRQS_DISABLED
+# define invoke_softirq()	__do_softirq()
+#else
+# define invoke_softirq()	do_softirq()
+#endif
+
+/*
+ * Exit an interrupt context. Process softirqs if needed and possible:
+ */
+void irq_exit(void)
+{
+	preempt_count() -= IRQ_EXIT_OFFSET;
+	if (!in_interrupt() && local_softirq_pending())
+		invoke_softirq();
+	preempt_enable_no_resched();
+}
+
 /*
  * This function must run with irqs disabled!
  */